The wireless ones are the easiest to install and I would hazard a guess
that they will last longer (I've had one cyclocomputer that died because
its connecting wire got damaged.) Most of the computers display 2
functions at a time. You cycle between them by pressing a single button.
The one I got recently, and like the most (although not wireless), displays
3 functions at a time and I like the fact that I can display distance,
speed, and cadence simultaneously. (It's the Echo-J12 and I bought it from
Bike Nashbar's catalog.) The current speed is always displayed and the
button-press cycles between average speed/ average cadence,
distance/cadence, maximum speed/maximum cadence, etc. Personally, the
functions I find useful are, in order of descending importance: distance,
speed, average speed, cadence, time.
13. Cycle Computers